Reversible air circulating system



March 6, 1945. V Q SQLBERG 2,370,886

REVERSIBLE AIR CIRCULATING SYSTEM Filed July 7, 1942 1 sheets-sheet 1 INVENTOR ATTORNEY L. o. SOLBERG 2,370,886

REVERSIBLE AIR CIRCULATING SYSTEM March 6, 1945.

FiledEJuly 7, 1942 4 Sheets-Sheet 2 l u l6. 0. JOZHE/EG.

ATTORNEYS March 6, 1945.

| o. soLBERq REVERSIBLE A IR CIRCULATING SYSTEM 4 Sheets-Sheet 5 Filed July 7, 1942 m R 0E 0 m w w L ATTORNEYS 4 Sheets-Sheet 4 L. o. SOLBERG REVERSIBLE AIR CIRCULATING SYSTEM Filed July 7, 1942 March 6, 1945.

INVENTOR Luow/e O. SOLBE/fi /6ao, W3

ATTORNEYS Patented Mar. 6, 1945 UNITED STATE s PATENT OFFICE forced air circulation, now generally in use,

wherein the cooling air is propelled or drawn through a cooling unit, thence delivered into ducts which convey it toand discharge it into the area to be cooled, thence to return through other ducts to the starting point for recirculation through the system.

To impart a better understanding to the objects and advantages of the improvements embodied by the present invention as applied to one of the typical uses of such systems, it will be here explained that apples may be kept for an extremely long time in good edible condition, without loss of firmness and flavor, if maintained in air of appropriate humidity and a temperature of approximately 31 F. However, to insure the safe keeping of the fruit, it is required that it be picked when at a certain exact condition of ripeness, that the field heat be immediately reduced and finally the core temperature of the apple be established at the above stated degree of temperature and that that temperature be maintained in the apple during its period in storage.

stacked first along the outside walls ofthe storage-area and the filling of the space progresses from the outside walls toward the center line of the area. Therefore. the cold air, as delivered into the area along the center line of the building must flow a distance equal to half the width of the area and consequently takes up heat from the intermediate air and objects before it reaches the fruit.

Furthermore, in the filling of the storage space, the workmen who bring the fruit into the area on hand trucks, are directly subjected to the chilling blast of cold air which creates a very bad health condition.

It is also an objectionable condition that, in a one-way system of circulation, the fruit nearest the points of supply of cold air will be cooled to a lower degree of temperature and there can be no uniformity of condition throughout the area. Therefore, in order to reduce the temperature of the fruit that is farthest away to the desired degree, it is necessary to cool that which is close, to a degree below that which is considered best.

In view of the objections and conditions set out in the foregoing explanatory matter, further objects of the present invention are:

To provide means whereby the direction of circulation of the cooling air may be reversed at will as a means of expediting the extraction of field heat from the apple, and thereby making it possible to approach a uniformity of temperature in all parts of the storage area; to employ lower temperatures during the initial cooling off period without danger of freezing the fruit, and to improve the health conditions of the workmen in filling the storage area.

Furthermore, to provide a system of ducts for the cooling air in connection with dampers operable for the reversal of direction of air flow, whereby this reversal in the storage area is accomplished without change in the direction of air flow through the cooling unit, and thus making possible the washing of the air in each cycle of its travel.

Also, to provide a novel system of ducts for the distribution of cooling air, in combination with a circulating fan, an air cooling unit and an arrangement of dampers whereby the direction of air flow may be reversed, controlled and regulated without change in direction of the fan or direction of air through the cooling unit.

Still further objects of the invention reside in the variousnovel details of construction of the building, and in the arrangement of ducts and combination of parts and their mode of operation,

as will hereinafter be fully described.

In accomplishing these and other objects of the invention, I have provided the improved details of construction, the preferred forms of which are illustrated in the accompanying drawings, wherein- Fig. 1 is a cross sectional view lengthwise of a building equipped with an air circulating and Fig. 1.

Fig. 5 is a detail oi damper control means.

' Referring more in detail to the drawings- The building here illustrated is merely representative of one form of construction that is suitable for the storage and cooling of apples, and it is to be understood that the materials from which it is made, its general details of construction, its dimensions and number of stories or floors, might be varied to meet special conditions or specific requirements. As here shown, the building, designated in its entirety by numeral I, has three floors, designated respectively by reference numerals 2, 3 and 4, and it provides three rooms or areas, designated by letters a, b and c, for the storage of the boxed r crated fruit. The first and second floors, 2 and 3, are of solid, that is, of air-tight construction, while the third floor 4, is formed of spaced planks, providing for flow of air through the floor for the cooling of both areas b and c by air delivered from the same supply ducts, as presently will be explained. The floor 3 serves as a ceiling for the area a, while the area 0 has an airtight ceiling 5.

Erected at the top of the building, centrally thereof and extending in its longitudinal direction, is a penthouse 6 for the air propelling fan and cooling means. Preferably, the fan is motor driven and is of the Sirocco type here designated by reference numeral it]. It is mounted on a shaft II and is contained within openings i3 registering with the opposite ends of the fan. This housing i2 has an air discharge duct l4 leading therefrom directly into an air cooling unit designated at i5, including pipe coils IS in suitable number and kind, to reduce the air to a desired degree of temperature, and at the outlet of the cooling unit, are free moisture eliminat'ors I8. Leading from the housing of the air cooling unit i is a downwardly and rearwardly directed air delivery duct ll, through which the cooled air is distributedto ducts, presently described, for delivery to, the areas to be cooled.

The present duct system, which may be understood best by reference to Fig. 3, comprises an upper duct 20 for accommodating the two upper areas b and c, and a lower duct 2| for accommodating the lower area a. Each of these ducts 20 and 2] extends horizontally, lengthwise of the building, and medially of and through the full length of the area it is to accommodate. Also, each duct is located adjacent the ceiling, or top of the accommodated area. The duct 2 I, at that end of the building which, for convenience in reference, will be referred to as the back end, has a vertical leg 2; extending upwardly therefrom, and this communicates at its upper end with the lower end of the duct I! through the rear end wall of the latter, as noted best in Fig. 1. Likewise, the duct 20 communicates with the duct I! through its bottom wall and immediately adjaicent the communicating connection with duct 2 a.

Within the duct i'l there is a hingedly mounted damper deflector plate, or valve 23, that is manually adjustable to different positions for the purpose of proportionately dividing the volume of cold air as supplied through duct H for delivery to the two ducts 20 and 2| so as to proportionately accommodate the areas supplied.

The ducts 20 and 2i have openings 24 formed at intervals therealong in their bottom walls through which air may be discharged into or received from the areas which ,these ducts accommodate.

Also, communicating with the duct I1. and

opening thereinto through an opening in its bottom wall between the opening for communication with duct 2| and its connection with the cooling unit, is a duct 25 used in the reversing of direction of flow of circulated air. This duct extends horizontally and is directly below the cooling unit and fan, lengthwise of the building and directly above duct 20. It extends to the front end wall of the building, where it is divided into two branches that continue as oppositely directed, horizontal ducts 251' and 25L, respectively, to the opposite front corners of the building. At the near corner of the building, as viewed in Fig. 3, the duct 251' communicates with a horizontal duct 21 that extends along the side wall of area c, below ceiling 5, to the rear end wall'of the building. Also, .there is a duct 28 that extends directly downward from the outer end of duct 251 to below the first floor and then turns and continues horizontally along the ceiling to the rear corner of the area a. Likewise, the duct 25L communicates at its outer end with a horizontal duct 29 that extends, horizontally along the side wall of the building, adjacent the ceiling of area c and to the rear wall, and there is a duct 30 that extends downwardly from the end of duct 25L to the lower area a, then .turns rearwardly and extends along the ceiling of that area to the rear corner of the building.

'The ducts 21 and 29, also the horizontal portions of ducts 28 and 30, are provided in their bottom walls at regular intervals with openings '32 for the inflow or outflow of air.

Contained within the outer end portions of duct 251 and leading up to the junction of ducts 21 and 28 therewith, is a division baflie 35 designed to proportionately divide the flow of air as delivered to the ducts 21 and 28. Likewise, located in the outer portion of duct 25L is a similar baffle designed for dividing the fiow of air to ducts 29 and 30.

The penthouse 6 which encloses the fan lll the cooling unit I5 and the duct ll therein, is airtight, and, in fact forms a longitudinal duct 40 enclosing these parts. At one end, the duct 40 communicates directly through an opening 42 in the top'wall of duct ll, with the'ducts 20 and 2|. The opening 42 is fitted with a damper 43 that is adapted to be adjusted between open and closed positions to permit or prevent flow of air through the opening.

Located within the duct H to close it against longitudinal flow of air therein, is a damper 45. This is disposed between the opening into the duct 25 and opening into duct 20, and it may be adjusted between open and closed positions. Also, there is a damper 46 in the entrance opening from duct I1 into duct 25, and this damper likewise is adjustable between open and closed positions. y i

In the top wall of duct 25 is an opening 48 providing direct communication with one end of the duct 40, and this opening is fitted with a damper,

. 49 adapted to be moved between closed and open positions, to prevent or to permit flow of air to the duct 40 from duct 25. Also, located in the duct 25 between the damper 49 and damper 46, is a damperlll, and this is adjustable between open and closed positions.

In the present drawings. the various dampers. as best shown in Fig. 4, have been illustrated as of the pivoted louvre type. It is to be understood, however, that various ways and means might be employed for the control of these dampers, and it is not the intent that the'invention shall be by any suitable means. In Fig. of these drawmode of use is as follows:

At the start of filling the storage rooms, the

boxed fruit is stacked along the side walls of the rooms, thus leaving the center space open for convenience of the workmen. As the filling of the areas continues, the stacks of boxed fruit prograss toward the center of the areas; it being understood that the stacking of boxes is such as to permit the required or desired circulation of cold air through and about the boxes for the uniform cooling of all. While workmen are operating in the rooms, it is desirable that the direction of air circulation be so controlled that the cold air will enter the areas from the ducts that are near the side walls, thus to-avoid the direct discharge of cold air from the central ducts 20 and 2| onto the workmen which is detrimental to their health.

In order that the cold air may be directed into By reason of periodic reversal of the direction of flow of cold air, a more uniform temperature may be maintained throu hout the areas to be cooled, and the objectionable feature found in the one-way systems, of keeping fruit that is nearest to the inlet of cold air always at a lower degree than that fruit farthest away, is avoided.

By reason of the provision for reversal at will of direction of flow of cooling air, the field heat may. be more quickly extracted from the fruit,

- for the reason thatit is possible to employ air the areas from the ducts that extend along the side walls, that is, from the ducts 21, 28, 29 and 30, the dampers 45 and 49 are closed and dampers 42, 46 and 50 are opened. The air, discharged by the fan 50, then enters. duct [1 from the cooling unit, is directed through open damper 46 into duct 25, passing therealong through damper 50, then continuing along the duct into the laterally directed ducts 251 and 25L to the ducts 21, 28, 29 and 30, to be discharged from these into the areas to be cooled. This cooling air flows toward the central zones of the areas, and is ultimately drawn into the ducts 2B and 2|, and is returned thereby into the lower end of duct l'l, passing directly upward through the open damper 43 into duct and is conveyed therein back to the fan, passing thereto through the openings [3 in the opposite end walls of the fan housing. This direction of circulation is opposite that which has been indicated by the arrows in the drawings.

For the reversal of the direction of air flow, the dampers 45 and 49 are opened while the dampers 42, 46 and 50 are closed, as has been shown in Fig. 10. Then the return air delivered to the fan is discharged, as before, through the cooling unit into duct I1 and is delivered through open damper 45 to the ducts 20 and 2|, to be conveyed therein directly to the areas to be cooled and discharged through the duct openings 24 into these areas along the center line of the building.

Among the many advantages to beobtained inv the present system are the following:

at lower temperatures, for example, below 30 F., and to avoid freezing the fruit'nearest the air delivery points by reversing the direction when that degree in the fruit, near the freezing point, is reached.

Due to the fact that the field heat can be more quickly extracted from the fruit, the expense of this very heavy load immediately following the filling of the building, is materially reduced, and then'during the entire storage period, the desired temperature may be uniformly maintained, at lower cost, by reason of the provision for periodic reversal of direction of flow.

The provision for causing the cold air to be discharged directly from the side wall ducts against the fruit as stacked along the outside walls, while workmen build the stacks toward the center of the areas, avoids loss of low temperature by reason of long distance of travel of cold air in .reaching'the fruit and also avoids the discomfort to the workmen and the unhealthful conditions of a. direct discharge of cold air into the central working areas.

It is evident that the size of 'the building-the disposition of areas, and the arrangement and design of ducts is not material to the invention so long as the spirit and objects of .the invention are retained. Therefore, itis not desired that the claim shall be restricted or confined to dedirection between the ducts, of an air condition ing and circulating unit comprising a housing having an air inlet and having an air discharge duct and means in the housing for conditioning the air in passing therethrough and for effecting a forced one-way flow of air through the unit; said air discharge duct having individual outlets connected with the two ducts of the system, valves applied to said outlets, one to be opened and the other to be closed to selectively determine the direction of flow of conditioned air through the storage area, an enclosure about the unit forming a passageway in open communication with the said air inlet of the unit housing and having'individual return passages from the two ducts of the system, valves in said last mentioned openings, one to be opened and the other closed to provide for return of air to the conditioning unit through one duct while the other is used for the delivery of conditioned air to the area.

. LUDWIG O. BOLBERG. 

